Instructions

1. Grease and line an 8 or 9-inch square baking pan with parchment paper. Make sure that the parchment paper extends past the pan to make the bars easier to remove from the pan. Set the prepared pan aside.
2. Break down the shortbread cookies in a food processor to make the shortbread layer until it resembles coarse beach sand.
3. Add 7 tablespoons (85 grams) of melted butter to the crumbs and mix until the crumbs are thoroughly coated in the butter.
4. Press shortbread mixture into the base, being sure to get it to the edges of the pan. Use the base of a cup or the back of a spoon to firmly press the crumbs into an even layer in the pan.
5. Place the pan in the fridge until firm. (I allowed an hour, but I don’t think it would need so long to chill.)
6. When you are ready to make the caramel filling, combine all of the caramel ingredients (brown sugar, unsalted butter, and sweetened condensed milk) into a small saucepan over medium heat.
7. While continuously mixing, allow the caramel mixture to come to a boil. Once it reaches a boil, push the heat down to low and simmer until thickened. Be careful to not burn the caramel on the bottom of the pan.
8. Carefully pour caramel over the shortbread crust into an even layer. Return the baking pan back to the fridge to firm up the caramel before continuing on.
9. Once the caramel layer has chilled, you can move onto the chocolate layer. In a microwave-safe bowl, melt the semi-sweet chocolate chips. Microwave the chocolate chips for 30 seconds, and then 15-second increments after that. Make sure to stir between each interval. Remove from the microwave before the chocolate chips are fully melted and allow the remaining chips to melt while you continue to stir the chocolate chips..Add in the butter and continue to stir until the butter is fully melted and combined.
10. Carefully pour the melted chocolate over the caramel mixture and spread it into an even layer. Return the pan back into the oven to chill for a few hours. Once the pan is thoroughly set, you can pull the bars out by lifting the edges of the parchment paper up and out of the pan.
11. Use a sharp knife to cut bars into small squares, being sure to wipe the knife between each cut to avoid getting crumbs from the shortbread onto the top of the chocolate layer. If the chocolate is cracking while you cut, let it sit for about half an hour to come to room temperature a bit before slicing.